System for active noise control with adaptive speaker selection

• US 8,077,873 B2
• Filed: 05/14/2009
• Issued: 12/13/2011
• Est. Priority Date: 05/14/2009
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Inventors: Shridhar, Vasant, Wertz, Duane
• Primary Examiner(s): NGUYEN, PATRICIA T
• Application Number:
  US12/466,282
• Publication Number:
  US 20100290635A1
• Time in Patent Office: 943 Days
• Field of Search: 381/71.1, 381/71.4, 381/302, 381/94.1
• US Class Current: 381/71.1
• CPC Class Codes: G10K 11/17817 between the output signals and the error signals, i.e. secondary path
• CPC Class Codes: G10K 11/17825 Error signals
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17879 using both a reference signal and an error signal
• CPC Class Codes: G10K 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone
• CPC Class Codes: G10K 2210/111 Directivity control or beam pattern
• CPC Class Codes: G10K 2210/1282 Automobiles
• CPC Class Codes: G10K 2210/3016 Control strategies, e.g. energy minimization or intensity measurements

Abstract

An active noise control system generates an anti-noise signal to drive a first speaker group including at least one speaker to produce sound waves to destructively interfere with an undesired sound in at least one quiet zone. The active noise control system receives error signals representative of a combination of undesired sound and destructively interfering sound waves produced by the first speaker group. The active noise control system may select a second speaker group to replace the first speaker group based on the error signals.

Claims

1. An active noise control system comprising:

a memory in communication with a processor;

where the processor is configured to select a first speaker group from a plurality of speakers, where the first speaker group is selected to receive a corresponding anti-noise signal configured to drive the first speaker group to produce sound waves to destructively interfere with an undesired sound present in at least one quiet zone;

the processor further configured to receive a first error signal, where the first error signal is representative of a combination of sound waves produced by the first speaker group and the undesired sound detected in the at least one quiet zone;

the processor further configured to determine when a second speaker group different than the first speaker group is configured to produce a second error signal less than the first error signal, where the second error signal is representative of a combination of sound waves produced by the second speaker group and the undesired sound detected in the at least one quiet zone; and

the processor further configured to replace the first speaker group with the second speaker group.

2. The active noise control system of claim 1, where the processor is further configured to select at least one speaker not included in the first speaker group to receive a corresponding anti-noise signal configured to drive the at least one speaker for a predetermined amount of time to produce sound waves to destructively interfere with the undesired sound present in the at least one quiet zone.

3. The active noise control system of claim 2, where the processor is configured to receive a third error signal, where the third error signal is representative of a combination of sound waves produced by the at least one speaker, the first speaker group, and the undesired sound detected in the at least one quiet zone.

4. The active noise control system of claim 3, where the processor is configured to select the at least one speaker to replace a first speaker in the first speaker group to form the second speaker group when said third error signal is less than the first error signal.

5. The active noise control system of claim 1, where the processor is further configured to simulate sound wave production by the second speaker group based on a signal representative of the undesired sound and the first error signal;

the processor further configured to determine a first simulated error signal based on the simulated sound wave production.

6. The active noise control system of claim 5, where the processor is further configured to replace the first speaker group with the second speaker group when the first simulated error signal is less than the first error signal.

7. The active noise control system of claim 1, where the first error signal is a plurality of error signals, where each error signal is produced by an error sensor, where each error sensor is positioned within a respective quiet zone, and where the processor is further configured to correlate a relative speaker position for each of the plurality of speakers and a relative error sensor position for each of the plurality of error sensors.

8. The active noise control system of claim 7, where the processor is further configured to determine a direction of the undesired sound based on the relative speaker positions and the relative error sensor positions.

9. The active noise control system of claim 8, where the processor is further configured to select the second speaker group based on the direction of the undesired sound.

10. The active noise control system of claim 9, where the processor is configured to select at least one speaker to be included in the second speaker group, where the direction of the undesired sound is more planar with sound waves produced by the at least one speaker to be included in the second speaker group than with at least one speaker included in the first speaker group.

11. A method of operating an active noise control system, the method comprising:

selecting a first speaker group from a plurality of speakers with a processor, where the first speaker group is selected to receive a corresponding anti-noise signal configured to drive the first speaker group to produce sound waves to destructively interfere with an undesired sound present in at least one quiet zone;

receiving a first error signal with the processor, where the first error signal is representative of a combination of sound waves produced by the first speaker group and the undesired sound detected in the at least one quiet zone;

determining with the processor when a second speaker group different than the first speaker group is configured to produce a second error signal less than the first error signal, where the second error signal is representative of a combination of sound waves produced by the second speaker group and the undesired sound detected in the at least one quiet zone; and

the processor replacing the first speaker group with the second speaker group.

12. The method of claim 11, where the processor is further configured to simulate sound wave production by the second speaker group based on a signal representative of the undesired sound and the first error signal;

the processor further configured to determine a first simulated error signal based on the simulated sound wave production.

13. The method of claim 12 further comprising:

simulating production of sound waves from a third speaker group with the processor, where the third speaker group is the first speaker group with an exclusion of at least one speaker from the first speaker group;

determining a second simulated error signal with the processor based on the simulated production of sound waves from the third speaker group;

comparing the first simulated error signal to the second simulated error signal with the processor; and

selecting one of the second speaker group or the third speaker group with the processor to replace the first speaker group based on the comparison of the first simulated error signal and the second simulated error signal.

14. The method of claim 13, further comprising:

the processor replacing the first speaker group with the second speaker group based on the first simulated error signal when the second speaker group is selected; and

the processor replacing the first speaker group with the third speaker group based on the second simulated error signal when the third speaker group is selected.

15. The method of claim 12, further comprising:

simulating production of sound waves from a third speaker group with the processor, where the third speaker group is different from the first speaker group and the second speaker group, where the simulated production of sound waves from the third speaker group is based on the first error signal and the signal representative of the undesired sound;

determining a second simulated error signal based on the simulated production of sound waves from the third speaker group with the processor;

the processor comparing the first simulated error signal to the second simulated error signal; and

selecting one of the second speaker group or the third speaker group with the processor to replace the first speaker group based on the comparison of the first simulated error signal and the second simulated error signal.

16. The method of claim 15, further comprising:

replacing the first speaker group with the second speaker group based on the first simulated error signal when the second speaker group is selected; and

replacing the first speaker group with the third speaker group based on the second simulated error signal when the third speaker group is selected.

17. The method of claim 15, where simulating sound wave production by the second speaker group comprises simulating sound wave production by the second speaker group from the plurality of speakers, where the second speaker group includes at least one speaker included in the first speaker group.

18. A computer-readable medium comprising a plurality of instructions executable by a processor to operate an active noise control system, the computer-readable medium comprising:

instructions to select a first speaker group from a plurality of speakers, where the first speaker group is selected to receive a corresponding anti-noise signal configured to drive the first speaker group to produce sound waves to destructively interfere with an undesired sound present in at least one quiet zone;

instructions to receive a first error signal, where the first error signal is representative of a combination of sound waves produced by the first speaker group and the undesired sound detected in the at least one quiet zone;

instructions to determine when a second speaker group different than the first speaker group is configured to produce a second error signal less than the first error signal, where the second error signal is representative of a combination of sound waves produced by the second speaker group and the undesired sound detected in the at least one quiet zone; and

instructions to replace the first speaker group with the second speaker group.

19. The computer-readable medium of claim 18 further comprising instructions to select each of the speakers not included in the first speaker group to receive a corresponding anti-noise signal configured to drive the each of the respective speakers for a predetermined amount of time to produce sound waves to destructively interfere with the undesired sound present in the at least one quiet zone.

20. The computer-readable medium of plain 19 further comprising instructions to receive a respective temporary error signal for the each of the speakers not included in the first speaker group, where each respective temporary error signal is representative of a combination of sound waves produced by the each of the respective speakers not included in the first speaker group, the first speaker group, and the undesired sound detected in the at least one quiet zone.

21. The computer-readable medium of claim 20, further comprising instructions to select a replacement speaker to include in the second speaker group, where the replacement each of the speakers not included in the first speaker group having a lowest temporary error signal relative to other temporary error signals.

22. The computer-readable medium of claim 21, further comprising instructions to replace a speaker included in the first speaker group with the replacement speaker.